1. Field of the Invention
The present invention relates to a wiper device for wiping a glass pane of a vehicle window, in particular, the windshield of the front passenger seat.
2. Description of the Related Art
In general, a wiper device for a vehicle has a wiper arm which swings on a surface of a window pane, and the tip of the wiper arm of a wiper blade moves back and forth in an arc. Since the surface of the window pane is generally rectangular, areas in the corners of the window pane can not be wiped out.
U.S. Pats 4,683,605 and 4,720,885 (which correspond to JP-A61-181745) disclose a four-joint-link mechanism. The four joint link mechanism is composed of a drive link connected to a motor and rotatably secured to a portion of a vehicle, a control link rotatably secured to a portion of the vehicle, and a coupling link for coupling the drive link and the control link via two movable joints. Although this mechanism increases the wiping area by a length of the drive link, the size of the mechanism is not sufficiently compact.